Health and Safety
Executive / Commission
Nuclear
LLC reports
This report is issued as part of the Health and Safety Executive's commitment to make information about inspection and regulatory activities relating to the above site available to the public. It is for distribution to members of the Dungeness Site Stakeholder Group (SSG) and covers activities associated with the regulation of safety at Dungeness B Power Station. These reports are distributed quarterly. Site Inspectors of HM Nuclear Installations Inspectorate (part of the Health and Safety Executive's Nuclear Directorate) attend LCLC meetings and will be happy to respond there to questions raised by members of the LCLC. Any person wishing to inquire about matters covered by this report should contact the HSE, Nuclear Directorate on 0151-951-3484/3290 .
This report will be placed on the HSE website at http://www.hse.gov.uk/nuclear/llc/index.htm under “Local Liaison Committee Reports”.
The Nuclear Installations Inspectorate (NII) Site Inspector visited Dungeness B on the following dates during the quarter covered by this report:
Other NII inspectors with specialist technical expertise also visited Dungeness B and other British Energy establishments during the period to support the Site Inspector by performing inspections on specific aspects of the Licensee’s arrangements and nuclear safety case.
The handover of site inspection responsibility for Dungeness B to the new nominated site inspector took place, in accordance with NII’s routine arrangements.
Routine planned inspections are carried out throughout the year and enable NII to judge whether a Licensee is complying with the conditions attached to the Nuclear Site Licence, the Ionising Radiations Regulations, and other relevant statutory provisions on a sampling basis. Compliance with the following Licence Conditions was inspected during the period:
In general the station’s arrangements were found to be satisfactory. In those areas where improvements were identified, satisfactory commitments to address the issues were made by the station. Routine aspects of particular significance are summarised below.
Reactor 21 shutdown for its three yearly statutory maintenance period on 14 May 2006. NII Inspectors with specialist technical expertise carried out inspections in the following areas:
NII concluded that the arrangements being implemented at Dungeness B were broadly satisfactory.
As part of their planned inspection site inspectors examine safety-related events that have occurred and the Licensee’s response to them. Generally the Licensee’s internal system for following up events is robust and the appropriate actions are implemented. More noteworthy events followed up during the period include the following:
As previously mentioned, in the Spring of 2005 NII became concerned that 9 fuel elements with very small defects were known to be present in the two operating reactors. Whilst recognising the low probability that any one defect would develop into a significant failure, we pressed for early removal of the defective fuel elements.
The Licensee subsequently committed to a programme under which all elements known to be defective should have been removed from the reactors by April 2006. Although delayed by the repairs required on the fuelling machine, Dungeness B has now removed all defective fuel elements.
The Licensee identified a need to change two wheel bearings on the Fuelling Machine. This required one side of the structure to be jacked up slightly (by around 7 millimetre) to enable the wheels to be removed. NII specialists monitoring the Licensee’s proposals for this work, which had the potential to have serious nuclear safety implications if inadequately conceived or executed. NII specialists, along with the nominated site inspector, monitored the implementation of this work which was successfully completed and the fuelling machine returned to service.
The station discovered that between 15 and 30 May 2006, the water Spray Fire system had two isolations as opposed to the limit of one isolation allowed by the station’s Operating Rules, (known as Technical Specifications), when a reactor is operating. The site inspector has reviewed the Licensee’s preliminary response to this event and is content with the actions taken.
Under Health and Safety legislation the Site Inspector, or other HSE Inspectors, may issue formal notices to secure improvements to safety. No such notices were issued during the reporting period.
The Inspectorate has powers under the Licence to issue Consents, Approvals and Directions. In addition the Inspectorate uses Licence Instruments to issue Specifications and Agreements under the conditions of the Licence. These are all called Licence Instruments. In accordance with formal regulatory procedure, NII issued the following Licence Instrument to Dungeness B under Site Licence No. 61 during the reporting period:
Licence Instrument No. 510 was issued on 28 April 2006 agreeing to the extension of the period of operation of reactor 21.